Effect of spray volume, spray pressure and adjuvant volume on efficacy of sethoxydim and fenoxaprop- p-ethyl

Abstract

Research was conducted at the Brandon Research Centre to determine the effect of altered spray volume by altered forward speed of travel, spray pressure, and adjuvant volume on sethoxydim or fenoxaprop- p-ethyl efficacy on Avena sativa. The efficacy of either herbicide was greater at 400 kPa spray pressure compared to 100 kPa pressure, suggesting that reducing spray pressure to reduce off-target drift may reduce herbicide efficacy. A. Sativa control with sethoxydim was not influenced by change in adjuvant volume from 0.5% ( v v ) to 2.0% ( v v ). However a minimum adjuvant volume of 0.3% ( v v ) was required with fenoxaprop- p-ethyl. Sethoxydim efficacy increased as spray volume decreased from 100 l ha −1 to 25 l ha −1; in contrast, fenoxaprop- p-ethyl control of A. Sativa was similar at all spray volumes used. These results indicate that decreasing spray volume by increasing forward speed of travel will not decrease the efficacy of fenoxaprop- p-ethyl and can enhance sethoxydim efficacy.